Catching students up who have fallen behind academically is a key challenge for educators, and can be difficult to do in a cost-effective manner. This field experiment examines the causal effect of a program designed to provide struggling sixth and seventh graders with math instruction delivered in small groups of roughly ten students by select teachers over weeklong vacation breaks. The program was implemented in a set of low-performing Massachusetts middle schools undergoing turnaround reforms. Attendance at these "Vacation Academies" increased the probability that students scored proficient or higher on Common Core-aligned math exams by 10 percentage points and reduced students' exposure to exclusionary discipline by decreasing out-of-school suspensions post-Academy. I find suggestive evidence of positive spillover effects on English Language Arts achievement and end-of-course grades in math and reading. Participants assigned to a single primary teacher for the entire week saw larger reductions in out-of-school suspensions than did students who rotated through teachers specializing in particular lessons. However, teacher specialization was associated with greater test score gains, suggesting a trade-off in outcomes depending on program design. Overall, the program's low cost and lack of a highly competitive teacher selection process make it a scalable approach to individualizing instruction.